Folomkina, S., author
Moscow State Publishing House
Buku Referensi
edited by P. S. Falla
Clarendon Press, 1990
Buku Referensi
Segal, Louis, author
Frederick A. Praeger, 1959
Buku Referensi
O`brien, M.A., author
George Allen and Unwin, 1930
Buku Referensi
O`brien, M.A., author
Dover Publications, 1944
Buku Referensi